MP Desmond Swayne said he would “riot in the street” if a plan to fluoridate south Hampshire’s water was extended to the New Forest.

Southampton’s Primary Care Trust wants to fluoridate two-thirds of the city’s water, and some supplies in Totton, to reduce dental decay in poorer areas.

A 14-week public consultation ended before Christmas, and the board of Southampton’s PCT will vote on the plan next month.

Mr Swayne is anxious the fluoridation should never extend to the New Forest and the coast.

He said: “I’m vehemently against it, it’s a poison in my view. If people want to take it, it should be up to them.”

A Hampshire Primary Care Trust spokesman said they had no fluoridation plan for the New Forest or any other part of Hampshire.

This was because these areas had “a very different population, with very different health needs” compared to the Southampton area earmarked change.

A New Milton doctor is one of the campaigners against the Southampton plan.

Dr Anthony Fox from Barton-on-Sea told health chiefs fluoridation causes increases in birth defects and cancer.

A former GP and now a specialist in homeopathy, he is chairman of 80-strong and Dorset and New Forest Safer Water Society Group.

“There’s a stack of scientific evidence against it. Even the best results have never shown more than a 25 per cent improvement,” he told the Echo.

New Forest East MP Julian Lewis has described the consultation as a sham, but The South Central Strategic Health Authority, which organised the consultation, said no decision has yet been made.